Centering means for light sources in lighting fittings



B. D. COLLIER May 17, 1966 CENTERING MEANS FOR LI GHT SOURCES IN LIGHTING FITTINGS 3 Sheets-Sheet 1 Filed Aug. 27, 1963 I I J INVE TOR flew/v fiewo (5.44/58 ATTORNEYS B. D. COLLIER May 17, 1966 CENTERING MEANS FOR LIGHT SOURCES IN LIGHTING FITTINGS Filed Aug. 27, 1963 3 Sheets-Sheet 2 HM M W May 17, 1966 a. D. COLLIER 3,251,986

CENTERING MEANS FOR LIGHT SOURCES IN LIGHTING FITTINGS Filed Aug. 27, 1963 3 Sheets-Sheet 3 INVENTQQ BR/AN 0/2 v/o C04 4 /R BY \Aaw, MW

ATTORNEY$ Filed Aug. 27, 1963, Ser. No. 304,862

11 Claims. c1. Mil-44.26)

This invention relates to improvements in lamp assemblies, and in particular to a floodlight assembly employing a tungsten filament lamp.

It is an aim of the present invention to provide simple 1 and eflicient means whereby a lamp may be accurately focussed in its reflector.

According to the present invention, there is provided a lighting fitting comprising a directional reflector means, first sighting means located with respect to the reflector means, second sighting means in the form of an aperture through which a lamp bulb can extend so that the light source thereof lies between the first and second sighting means, and means for adjustment of the position of the light source relative to the reflector means, the arrangement being such that the light source can be centered in the reflector means by alignment of the light source with said first and second sighting means.

By the term lamp bulb, We mean an envelope in which a concentrated light source is positioned; the source can be, for example, in the form of a filament.

Features and advantages of the invention will appear from the following description of one embodiment thereof, given, by way of example, in conjunction with the accompanying drawings, in which:

FIGURE 1 is a side elevation, partly in section, of a floodlight assembly in accordance with the invention, the floodlight supports having been omitted;

FIGURE 2 is a partial end view of the assembly as seen on one side of a vertical plane through its central axis.

FIGURE 3 is a plan view upon the reflector end of the assembly; and

FIGURE 4 shows a modification of the first sighting means of the assembly.

Referring to the drawings, the floodlight assembly comprises a generally comically-shaped hollow body 1, the inside surface of which forms the main reflector, and an end housing 2 detachably connected to the body 1 and supporting a lamp socket 3. The body 1 is mounted on a pair of supports 4 one of which is shown in FIG- URE 2, and is capable of angular rotational movement about the supports in a vertical plane, it being possible to lock the body relative to the supports by means of a locking bar 5. Positioned at the forward end of the body 1 is a glass cover (shown dotted) which is held and located on the body by'a circumferentially extending retaining band 6 of channelled cross-section. As is shown in FIGURE 3, the glass cover 1A has a first sighting means in the form of a central annular ring 7 of suitable diameter etched on its surface, the purpose of the ring being as will be explained in more detail later, to aid in the centering of the filament lamp (shown dotted) in its reflector.

The housing 2 is retained on the body 1 by a plurality of Wings nuts 8 circumferentially positioned about a rear portion 1a of the body and which engage corresponding projections 9 integral with the housing 2, alignment of the housing and body being provided by the engagement of a shoulder 1b of the body with an annular groove 2a in the housing. Positioned between adjacent portions of the housing and body is a rear reflector 10 having a central aperture 11 through which the lamp may extend when held in its socket, The purpose of such a reflector United States Patent 0 is to reflect, into the body of the lamp assembly, those light rays which are emitted from the lamp filament in a backward direction, and to act as a heat-shield for the interior of the housing 2, the aperture 11 in the reflector 10 also being utilized in the centering of the filament and thus constitutes a second sighting means.

To provide positional adjustment of the lamp filament within the body 1, the lamp socket 3 is mounted on a rear wall of the housing 2 'by means of a ball-and-socket joint 12-. The ball portion is a part-spherical hollow member 13 to which the socket 3 is attached through a sleeve 14,

the wall of housing 2 is a recess 2b, the recesslocating a two-way connector 20 from which electrical connection can be made to the lamp socket 3. Power supply cables may reach the connector 20 through an apertured end cap 21 covering the recess 2b.

It will be apparent that the filament lamp can be centered in its main reflector simply by adjustment of the position of the lamp socket, by means of the ball and socket joint 12, until the filament is in alignment with the sighting ring 7 marked on the glass cover 1A and the aperture in the rear reflector 10, the rear reflector being coaxial with the main reflector.

Thus, a lamp assembly according to the present invention may be accurately centered in daylight, before installation and without the lamp alight.

In the case of a lamp assembly to be adjusted without a glass cover, an attachable crossbar 30 (see FIGURE 4) may be temporarily fitted to the mouth of the main reflector, the crossbar having a central sighting aperture 30A.

The embodiment hereinbefore described is particularly applicable to football field lighting, where a number of The lamp assembly of the invention lends itself to' accurate training since lamp housing 2 can be removed and a device including a telescope secured in its place; the telescope is mounted on a support plate which is secured to the body 1 by the Wing nuts 8 so that the telescope is located on the beam axis of the main reflector. The telescope is then sighted on the stake at the center of the area of the field to be illuminated, and bar 5 locked to secure the lamp assembly in its adjusted position; the telescope is now removed and replaced by the lamp housing 2.

Alternatively, the telescope may be arranged to be temporarily attached to the lamp assembly externally thereof and on an axis parallel to the reflector axis; in this case it can be arranged that by sighting the telescope on, say, the top of the ground stake, the reflector axis will be trained on the bottom of the stake at ground level.

In a further modification, the telescope may be attached externally of the lamp assembly so that its axis is divergent and angularly adjustable relative to the reflector axis; the adjustment being indicated by a scale marked in the length of beam throw, that is to say, the distance from the floodlight of a point where the axis of the telescope and the floodlight coincide on the ground; in this case, the telescope is adjusted to the beam throw required and then sighted on the marker stake.

What I claim is:

1. A light projector comprising a directionalreflector, a receiving means for a source of light, said receiving means being mounted in alignment with an optical lengthwise axis of the reflector, means for varying the position of said receiving means in reference to said optical axis, a first and a second sighting means supported by the red 7. A light projector according to claim 5, wherein said second reflector comprises a dished annular member disposed in a general plane transverse of said optical axis.

8. A light projector according to claim 2, wherein said socket is mounted by means of a ball and socket joint. 9. A light projector comprising, in combination, a generally conical directional reflector open at both ends, a socket housing detachably secured to the narrow end of the reflector, an electric connector socket for receiving an envelope including a source of light, pivotal mounting means pivotaliy supporting said socket in said housing in substantial alignment with the optical center axis of flector, said first and second sighting means being 10- catedon lengthwise opposite sides of a source of light received in said receiving means for centering the position of the received light source in reference to said optical axis of the reflector.

2. A light projector comprising a' generally curved directional reflector, a lamp socket pivotally mounted in alignment with the optical center axis of said reflector, a lamp including an incandescent filament insertable in said socket, a first and a second sighting means supported by said reflector, said sighting means being disposed concentrically with said optical axis on lengthwise opposite sides of the lamp inserted in said socket for centering the filament of the lamp in reference to said optical axis.

3. A light projector according to claim 2, wherein said first sighting means comprises a transparent cover covering the mouth of said reflector and a ring concentric with said optical axis on said cover.

4. A light projector according to claim 2, wherein said first sighting means comprises a bar having an aperture, said bar fitting the mouth of the reflector, the aperture of the bar being located concentric with said optical axis in the fitted position of the bar.

5. A light projector according to clairn'Z, wherein said first sighting means is supported by the reflector adjacent to the mouth thereof, and wherein said second sighting means is mounted in the reflector adjacent to the base thereof.

6. A light projector according to claim 5, wherein said second sighting means comprises a second reflector having a central opening coaxial with said optical axis.

the reflector, a first sighting means supported by the directional reflector at the wide end thereof, said first sighting means having a first sighting opening concentric with said optical axis, a second sighting means including a second reflector extending across the narrow end of the directional reflector, said second reflector having a second sighting opening also concentric with said optical axis, Said first sighting means being disposed forward and said second sighting means rearward of the source of light when said envelope is received in said socket.

10. A light projector according to claim 9, wherein said second reflector included in the second sighting means comprises a dished ring disposed in a general plane transverse to said optical axis, the central opening ofsaid ring constituting a passage for a source of light received in said socket. I

11. A light projector according to claim 9, wherein said mounting means for the socket comprises a ball and socket joint.

References Cited by the Examiner UNITED STATES PATENTS 1,821,763 9/1931 Miner 24044.2

2,327,820 8/1943 Rogers 240-3 2,870,362 1/1959 Arnold et al. 240 41 NORTON ANSHER, Primary Examiner.

CHARLES C. LOGAN, Assistant Examiner. 

2. A LIGHT PROJECTOR COMPRISING A GENERALLY CURVED DIRECTIONAL REFLECTOR, A LAMP SOCKET PIVOTALLY MOUNTED IN ALIGNMENT WITH THE OPTICAL CENTER AXIS OF SAID REFLECTOR, A LAMP INCLUDING AN INCADESCENT FILAMENT INSERTABLE IN SAID SOCKET, A FIRST AND A SECOND SIGHTING MEANS SUPPORTED BY SAID REFLECTOR, SAID SIGHTING MEANS BEING DISPOSED CONCENTRICALLY WITH SAID OPTICAL AXIS ON LENGTHWISE OPPOSITE SIDES OF THE LAMP INSERTED IN SAID SOCKET FOR CENTERING THE FILAMENT OF THE LAMP IN REFERENCE TO SAID OPTICAL AXIS. 